Apparatus for making tubular joints



J. L. MRAZ APPARATUS, FOR, MAKING TUBULAR JOINTS Se t, 10," 1929.

2 SheetsE-She Original Filed April 2, 1927 I INVENTOR Jbse v/v L. Mraz.

ATTORNEYS J. L. MRAZ APPARATUS FOR MAKING TUBULAR JOINTS Sept. 10, 1929.

Original Filed April 2, 1927 Z Sheets-Sheef 2 ATTIIORNEYSV Patented Sept. 10, 1929.-

:r'osarz mim z, or WATERBIURY, co vmzc'rrour;

arraimrusron mmerusumn Jomrsg This; application/i a division ofn' ympe plication -for'patent filed April 2, 1927; "Shria No. 180,390. i

An important object of the present invention-1 is to provide. a. simple apparatus f or .m ng-astrong joint between the ends of A solder.

'ing the joint shown in Figs. 16 and 17 and two 'electric conductors without: the use of Another object of the invei tion' is to;provide a.- simple and efli'cientapparatus for making a close joint of great tensile stren th between 'atubular metal structurefan a wire, stranded cable rod or the like.. a

hereinafter.

' Other objects of-the invention will appear In the drawings; a

4 Fig; 1 is aside'view, partly in s'ection,.of the assembled join't elements; priorto the com; pression' thereof;

Fig. 2 aside view, partly in section, showing theo'peration of compressingthe joint sleeve; v t A 7 Figs. 3, .4 and 5 enlarged cross-sectional views showing different stages of the compressing operation;

Fig. '6 a perspective view of the finished Figs.

7 and 8 a side view and-a longitudinal of forming another form ofjoint';

Fig. 9 a side view. of the finished joint; Fig. 10. a cross section taken on the line -10 10.of Fig. 7;' .j' Fig. 11 a similar view taken on the line 11.1I'of Fig. 7;

I -section respectively showingtheloperation Figs. 12 and 13 cross isec'tional views show -ing the manner of forming a 1 twooverlapped wires;

joint between Fig. 14 a side view of said lap joint partly broken away'; Fig. 15a plan view thereof;

Fig. 16 a side view o f another form of lap Fig. 17 a plan view thereof; t Fig. 18 a longitudinal section'upon-an enlarged scale showing the operation of; form'- "Fig.-j19 'a cross section taken on the' line i 19-19'of Fig. 18.

' 'To torni an improved joint between two T S J Original application fil e d A ril-2,1927, Serial No.-180;390. Divided and as application filed February a 16,- 1928. Serial 1 10.254577.

electric wirest I fi'rst' provide a tubular con-'1 though any suitable material may e used. The bore or passage 2 through the sleeve is s'hghtly'larger in diameter than the wires 'nector sleeve 1' elf-cylindrical form. -This sleeve isipreferably formed of co gper'alwhich are' 'to be'connected together, and the ends of 'safid bore-flare outwardly as at 3 to form bell-shaped entrances for thewires.

are thrust through the passage until they bottom against the abutments as showniht Fig. 1. .The tube is next compressed about the 1 The ends of the circuit wires 5 'are inserted into the opposite'e'nds of the passage 2 and wires in a manner'to intimately and perm-anently uniteit with theml, This compression is performed by two-die members 6 which are engagedw-ith opposite sides of the tube as shown in Fig. 2. The cross-sectional form" of these die members is-shown in Figs. 3, 4; and; 5. Each member is formed at its working face with a straight grodve'7. The surface of this groove is substantially semi-cylindrical and in cross section it describes an are slight ly less than-a semi-circle; 1 This are is struck witha radius slightly less than theradius of the cross section ofjthe cylindrical tube 1 which is to be operated uponby the die meme hers- Therefore when the diemembers are v brought into engagement with the cylindrical surface of the tube only. the edges 8 of the grooves 7 will contact with'the tube, as shown in Fig. 3. The edges 8 are rounded and their points of contact with'the tube are-spaced equally above and-jbelow 'the transverse center line .w-exte'nding horizontally through thetube. The die membersare-next pressed toward each'other. The resultant transverse pressure transmitted to the tube by the (lie, edges 8 as the members approach each other causes the tube to be compressed in substantially the direction of the line 11:, and .forces it tight 1y against the enclosed wire at'diametrically opposite point-s thereof. Thi'scompr'ession,

'distorts. the .tubeinto an elliptical cross-sectional .form, as shownin Fig. 4, and causes it to closely fit the die grooves the move ment of the die members continues, therefore,

the tube will be subjected to the pressure of the entire surfaces of .the grooves and will be Compressed in a direction substantially atright angles to the direction of the first compression andforce the tubeinto contact with the wire around the entire circumference 'thereof. During the final portion ofthe die movement it willbe observed that almost the.

entire'cross section of the tube is confinedbei binding contact with the entire circumference of the wire. During this final compression of the tube metal it is left free for a. nar- Y the direction of the line at.

row spacebetween the'eompressing die members to permitof a slight transverse deformation or upsetting of the metal outwardly in This deformation takes the form of two narrow ribs 9 extending longitudinally along the tube; lVhen the compression is completed the tube is again of cylindrical form but its diameter is now.,

reduced. The pressure has molded'the metal of the tube around the circumference of the wire. .Heat-is generated in the metal by the pressure and consequently when the tube cools it contracts into a still stronger bindingj engagement with the enclosed wire. The die members may beforced together either by sustained pressure or by blows.

The die members are shifted along the tube and a series .of compressing operations are- 1 performed until substantially the entire length of the tube has been cqlnpressed. The end portions of the tube are, however, left uncompressed in order to avoid crushing the flared entrances 3. These flared surfaces are provided not only to facilitate the insertion of the wires but also to avoid sharp corners and permit the wires to hand without any biting action at the points where they emerge from the tube. When the wire and the tube have been united .as desciibed the tube be-' comes in effect a permanent, integral part of the wires and the electrical conductivity. of

the joint will be equalto that of a continuous wire. The conductivity cannot be reduced in any way. The joint is substantial andthe sleeve is so intimately united with the wire as to entirely exclude moisture from the interior of the joint. v

'In Figs. 7, 8 and 10 I have illustrated an- I other form of apparatus for forming a joint having a great tensile strength in addition to possessing all of the advantages of the straight joint just described. A-tube of the form shown in Fig. 1 is used in forming this joint also and the wires 5 are inserted into said tube as shown in Fig. 1. I now employ die members 10 and 11 to operate upon the tube. These die members have substantially the same cross sectional form as the members 6 but differ from them in longitudinal sec tion. groovesurfaces l2-and -13 of the die srnembers 10. and 11 respectively are formed'in longitudinal section to force a portionof-the tube and the enclosed portion of the wireout of alinementwith the longitudinalcenter line or axis of the joint and form a curved bend. 14 therein. Toaccomplish this,

one of the die members is formed upon its tion the tube is compressed about the enclosed wire to give thejoint thesame cross sectional form as that of theprevious' joint, 5

the bending humps of the-die members andthe adjacent groove surfaces being formed to accomplish this, as shown in: Fig. 10. 'Outwardly of the bending humps the groove'surfacesof the .two di'e members extend longi- Q tudinally in parallel lines spaced apartsuflici'ently to avoid crushing, adjacent portions of the tube during a'bending and compressing operation. The performance of thecompressing operation simultaneouslywith the bending of the tube is a very desirable fea--'' ture. The compression of the tube prevents it fromsplitting under the bending stress, by ironing out the metal of the tube and maintaining the continuity of its outer surface.

, It also holds the tube in close contact with the entire enclosed surface of the wire as both are bent. i The -die members are advanced along the tube to perform a series of these bending and compressing operations and form a series of i the bends l4vateither side of the longitudinal center of the joint. Each bend merges with the nextjn the series so that the series pre sents a continuous, even, wave-like form.

.The degree to which the tube and wire are the enclosed surface of the wire provides a Q -closed-j oint ofhigh electrical conductivity without the use of any cementing material.- It" costs little to prepare the sleevefo'rcom nection and requires.very little equipment for makingthe joint. Another practical advam. .tage isthat it requires less skinning "of the" insulation from an insulated wire than in the case of an ordinary "overlapped and soldered jointfand needs 'less insulation to. coverit' when the connection is made.

lapped wires.- .A straight elongated sleeve 17 is here used. This sleeveis sufficiently elongated. or oblong .in cross section 'to accommodate two wires 18 side byside. .The ends of. the passage through the sleeve are flaredoutwardly'as at 19. The sleeve is compressed by means of two die members 20 and 21. .The member 21 is formed-with a relatively deep groo'ove 22. The width of the I groove 1s slightly les s than the major width of the sleeve. The sleeveand its enclosed wires are placed diagonally within the groove 22 with one end ofthe cross section of .the sleeve in'the bottom of the grogve and the other end projecting out of the groove as shown in Fig. 12. The die m'ember 2O is .formed withtwo shallow grooves.23 side by side and separatedby alongitudinal rib 24.- .The member 21 is formed with a similar rib 25 at the bottom of the groove 22. One

ofthe grooves23 is engaged with the projecting portion of the diagonally disposed sleeve 17 andthe die membeisare. pressed together-.- ---This pressure will force thesleeve 17 entirely into-the groove 22 andthe'sleveill be laterally-compressed between the op'-.

posite side wallsoi; the groove and opposite sides. of the' sleeve wilhbe forced into tight engagement Witl1-the-enclosed Wir es.-. As the a sleeve descends? into the groove 22 the .ribs

gagementvwith the portions of .the'sleeve extendingbje'tw-een'the wires,' pi*?erit*the sleeve from expanding at these points under the stress of the said lateral compressionaan 7 strength. The two die members 26 and 27 to those shown in Figs.

force the metalof-the sleeve inwardly be tween 'the -wires.. W hen the'sleeveha s been forced against the bottom 0f the groove as shown-in Fig. 13 its cross section is'almost entirely surrounded by the opposed concave die faces and a compression thereof. will force the metal of the sleeve into intimate-binding engagement with the" enclosed wires around substantially three-quarters of their circumference.

In Figs. 16 and 17a modification of the provided for this purpose are similar in form an d '8 except that in' cross' s'ection they correspond in form to; the

die members 20..and21,:' h 12 WhatI-cla'im is;

.1. apparatusfor compressing a metal l formedto engage the tube, compress it transmovement and permit theit'ube to expand in .a direction substantially at right angles-to the directionof said compression, and next to compress the tube transversely around substantia'lly, its entire circumference as the die movement progresses and force the metal of versely into contact. with two opposite sides I p of the strand during the first part of the die In Figs; 12to-15I-have shown the con-. struction of a joint for connecting two overthe tube into intimate binding contactwith.

the entire circumference of the strand. 2. An apparatus for compressing a metal tube aboutastrand enclosed in the tube, com

prising a pair of-die members-adapted to be. relatively moved toward each. other'j and formed to engagethe tube, compress it transverse'lyinto contact with two opposite sides' 0f the-strand during the first part ofthe die movement, andnext tocompress the. tube transversely around substantially its entire circumference, as the die movement pro-;

gresses and' force the metal of the tube intointimate binding contact with substantially the, entire circumference of the strand; and

means carried by the die memberstobend' the compressed portion of the tube and the enclosed strand simultaneously with the per- .formanceTotthecompression. -3'-'.fAn-apparatus for compressing a metal tube about a strand enclosed within the tube, comprising a-pair of opposed die mbers adapted to be relatively moved toward each -.other and each provided with a groove having rounded .marginal edges to engage opposit/e sides of the tube 'when the latter is d sposed between the die vmer'nbers, the two .gro'oveg when the die members'are brought togethemforming a cavity of smaller'cross" sectlonal dlmenslons than the cross sectional dimensions of thetube to be compressed, .gvherebyduring the compressing operation the tube will be compressed by the rounded marginal edges of the grooves transversely;

of the direction of movement of the die members into contact with opposite sides of the 4 strand during the first part of the die movement; and will'be then compressed in the di- 'rection of movement of the die members sub-- stantially atright angles '.;to the first'com pression during the final compressing movement of the die members, the-said die members during the final-portion of the compressing operation forcing the tubeinto direct close binding contact with the strand around its entire circumference.

tube about a strand enclosed within the tube, comprising a pair of opposed die members 4. Am apparatus for compressing a metal iso I the tube will be compressed by the rounded marginal edges of the grooves transversely of the direction of movement of the die mem-' bers into contact'with opposite sides of the strand during the first part of the die movement and will be then compressed in the direction vofmovement of the die members substantially at-right angles to the first compression during the final compressing movement of the die members, the said die members during the final portion of the compressing operation forcing the tube into direct close binding contact with the strand around-its entire circumference; and 'means carried by.

the die members to bend the compressed portion of the tube and the enclosed strand simultaneously with the performance of the compression.

- withthe wave-like curve of the groove in the 5. An apparatus for compressing a metal tube about a strand enclosed therein and interlocking it therewith to form a joint, comprising a pair of opposed die members adapt-' ed to be relatively moved toward eachother and .each provided with a groove in its WorK- ing face to engage opposite sides of the tube whenthelatter is disposed between them, the I two grooves forming a cavity of smaller' cross-sectional dimensions than the cross-sectional dimensions of the tube to be compressed; a tube-flexing projection formed upon the working face of one of said die members, of hump-like formin side contour, curved at the peak and at the base longitudinally of the said groove and forming a wavelike curve in the groove; and a pair of tubeflexing projections formed upon the working. face of the opposed die member, spaced apart longitudinally of the groove at opposite sides of a transverse plane through the center of the first projection and forming a, wave-like curve in the groove to cooperate other die member,'whereby the'die members are adapted to form a wave-like bend in both the tube and the enclosed strand and to re duce the cross-section of the .tube along said bend 'by compressing the tube about the strand.

6. An apparatus for compressing a metal tube about a strand enclosed therein and interlocking it therewith to form a joint, comprising a pair of opposed die members adapted to be relatively moved toward each other and each provided with a groove in its workingface to engage opposite sides of the tube whenthe latter is disposed between them, the

the two grooves forming a cavity of smaller cross-sectional dimensions than the crosssectlonal. dimensions of the tube to be compressed; at tube-flexing projection formed upon the grooved'working face of one'of 'said' die members, of hump-like form in side o0n tour and curved at'the-peak and-at the base longitudinally of the said groove to form a."

wave-like curve in the groove; apair of tube-' flexing projections formed upon the working face of the opposed die member, similar in .form to said first projection and spaced apart longitudinally of the groove at opposite sides of a transverse plane through-the. center of the first pro ection to form a wave-like curvein the groove to cooperate with the wave-like portion of the groovein the other die member whereby the die members are adapted to form a wave-like bend in both the tube and the enclosed strand and to reduce the. cross-section of the tube along said bend by com'pies'sing the tube about the strand, the opposed faces of thetwo' die members extending straight outward at opposite sides of their respective projections in parallel directions.

. 7. An apparatus for" compressing -a metal tube about a pairof-inetal strands enclosed therein side by side. to-form a joint, comprising a pair ofopposedfdie members adapted to be relatively moved'towardeach other to engage opposite sidesof thetube when the latter is disposed therebetween and formed with opposed working faces concave to pro- I vide opposed longitudinally extending grooves for embracingthe tube; a rib formed in one of said grooves and extending longie tudinally along the center thereof; an opposed longitudinal central rib formed in the other ,q'roov'e, wherebv the die members are adapted to compress the tube around and between the enclosed strands; and meanscarried. by

the die members to form a Wave-like bend 'in the compressed portion of the tube and the enclosed strands simultaneously with the performance of the compression.

-8. An apparatus for compressmg a metal tube about a air of strands enclosed therein and interlocking it therewith to form a joint,

comprising a pair of opposed-die members adaptedlto be relatively moved toward each other and each provided with a groove in its working face to engage opposite sides of the tube when thelatter is disposed between them, the two grooves forming a cavity of smaller cross-sectional dimensions than the crosssectional dimensionsofthe tube to be compressed; 2, tube-flexing projection formed upon the workin face of oneof said die members, of hump-1i e form in side contour and curved at the peak and at the base longitudinally ofthe said groove and forming a wave-like 'curve in the groove; a parrot tube flexing projections formed upon the working face of the opposed die member, spaced apart longitudinally of the groove at opposite sides of a transverse plane through the center of the first-projection and forming a wavelike curve in the groove to cooperate with the wave-like ortion of the groove in the other die mem er; a rib formed in one of said grooves and extending longitudinally along the center thereof; and an opposed long'itudinal central rib formed in' the other groove, whereby the die members are adapted to form a. wave-like bend in the tube and the enclosed strands and compress the tube around andrb'etween the strands.

9. An apparatus foricompressing a metal tube about a strandenclosed in the tube, com prising a .pairof die members adapted to be relatively inoveiltoward each other to engager'; the tube disposed therebetween and provided with die faces forming opposed. grooves to 1 embrace the tube and having longitudinally spaced, staggered projections in said grooves, said die faces being adapted to transversely compress the tube, form a wave-like bend in the tube and enclosed strand, and mold'the metal of the tube into intimate binding contact with the entire periphery of the strand along the length of said bend.

In testimony whereof I hereunto afilx iny signature. a g g so JOSEPH L. MRAZ. 

